In his Materialism without Reductionism: What Materialism Does not Entail, Richard Boyd answers Kripkeâs challenge to materialists to come up with a way to explain away the apparent contingency of mind-brain identities . Boyd accuses Kripke of an imaginative myopia manifesting itself as a failure to realize that the more theoretical term in the identity is fixed by contingent descriptions â descriptions that might pick out otherworldly kinds of neural events where C-fibres are absent. If this is something we can confuse in the imagination with actual C-fibre firings, then we have an explanation of the apparent contingency of the necessary identity âPain=C-fiber firings.â However, for this to succeed it must be the case that the reference of âC-fiber firingsâ is fixed by some contingent description, which is false. Boyd, I submit, has failed to answer Kripkeâs challenge after all